1. Field of the Invention
This invention relates generally to apparatus for mixing and spraying foam insulation and more particularly, but not by way of limitation, to such apparatus having purge air systems for cleaning of the passageways subsequent to the mixing of the foam components.
2. Description of the Prior Art
The prior art includes numerous devices for the mixing and application of foam insulation. Such apparatus generally include a mixing chamber wherein a first liquid component is mixed with compressed air, and a nozzle downstream of the mixing chamber whereby a second liquid component is ejected into the mixture of the first component and air. Most of those devices are, however, of a very bulky complex design including much external tubing.
The present invention provides a compact efficient apparatus for the mixing of components for foam insulation and also provides simple and efficient means for the cleaning of the apparatus by purging the orifices of the nozzle with air after the mixing operation.